drivers/net/virtio/virtio_rxtx_simple.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2015 Intel Corporation
   3  */
   4
   5 #include <stdint.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <errno.h>
  10
  11 #include <rte_cycles.h>
  12 #include <rte_memory.h>
  13 #include <rte_branch_prediction.h>
  14 #include <rte_mempool.h>
  15 #include <rte_malloc.h>
  16 #include <rte_mbuf.h>
  17 #include <rte_ether.h>
  18 #include <rte_ethdev_driver.h>
  19 #include <rte_prefetch.h>
  20 #include <rte_string_fns.h>
  21 #include <rte_errno.h>
  22 #include <rte_byteorder.h>
  23
  24 #include "virtio_rxtx_simple.h"
  25
  26 #ifndef __INTEL_COMPILER
  27 #pragma GCC diagnostic ignored "-Wcast-qual"
  28 #endif
  29
  30 uint16_t
  31 virtio_xmit_pkts_simple(void *tx_queue, struct rte_mbuf **tx_pkts,
  32         uint16_t nb_pkts)
  33 {
  34         struct virtnet_tx *txvq = tx_queue;
  35         struct virtqueue *vq = txvq->vq;
  36         struct virtio_hw *hw = vq->hw;
  37         uint16_t nb_used;
  38         uint16_t desc_idx;
  39         struct vring_desc *start_dp;
  40         uint16_t nb_tail, nb_commit;
  41         int i;
  42         uint16_t desc_idx_max = (vq->vq_nentries >> 1) - 1;
  43         uint16_t nb_tx = 0;
  44
  45         if (unlikely(hw->started == 0 && tx_pkts != hw->inject_pkts))
  46                 return nb_tx;
  47
  48         nb_used = VIRTQUEUE_NUSED(vq);
  49         rte_compiler_barrier();
  50
  51         if (nb_used >= VIRTIO_TX_FREE_THRESH)
  52                 virtio_xmit_cleanup_simple(vq);
  53
  54         nb_commit = nb_pkts = RTE_MIN((vq->vq_free_cnt >> 1), nb_pkts);
  55         desc_idx = (uint16_t)(vq->vq_avail_idx & desc_idx_max);
  56         start_dp = vq->vq_ring.desc;
  57         nb_tail = (uint16_t) (desc_idx_max + 1 - desc_idx);
  58
  59         if (nb_commit >= nb_tail) {
  60                 for (i = 0; i < nb_tail; i++)
  61                         vq->vq_descx[desc_idx + i].cookie = tx_pkts[i];
  62                 for (i = 0; i < nb_tail; i++) {
  63                         start_dp[desc_idx].addr =
  64                                 VIRTIO_MBUF_DATA_DMA_ADDR(*tx_pkts, vq);
  65                         start_dp[desc_idx].len = (*tx_pkts)->pkt_len;
  66                         tx_pkts++;
  67                         desc_idx++;
  68                 }
  69                 nb_commit -= nb_tail;
  70                 desc_idx = 0;
  71         }
  72         for (i = 0; i < nb_commit; i++)
  73                 vq->vq_descx[desc_idx + i].cookie = tx_pkts[i];
  74         for (i = 0; i < nb_commit; i++) {
  75                 start_dp[desc_idx].addr =
  76                         VIRTIO_MBUF_DATA_DMA_ADDR(*tx_pkts, vq);
  77                 start_dp[desc_idx].len = (*tx_pkts)->pkt_len;
  78                 tx_pkts++;
  79                 desc_idx++;
  80         }
  81
  82         rte_compiler_barrier();
  83
  84         vq->vq_free_cnt -= (uint16_t)(nb_pkts << 1);
  85         vq->vq_avail_idx += nb_pkts;
  86         vq->vq_ring.avail->idx = vq->vq_avail_idx;
  87         txvq->stats.packets += nb_pkts;
  88
  89         if (likely(nb_pkts)) {
  90                 if (unlikely(virtqueue_kick_prepare(vq)))
  91                         virtqueue_notify(vq);
  92         }
  93
  94         return nb_pkts;
  95 }
  96
  97 int __attribute__((cold))
  98 virtio_rxq_vec_setup(struct virtnet_rx *rxq)
  99 {
 100         uintptr_t p;
 101         struct rte_mbuf mb_def = { .buf_addr = 0 }; /* zeroed mbuf */
 102
 103         mb_def.nb_segs = 1;
 104         mb_def.data_off = RTE_PKTMBUF_HEADROOM;
 105         mb_def.port = rxq->port_id;
 106         rte_mbuf_refcnt_set(&mb_def, 1);
 107
 108         /* prevent compiler reordering: rearm_data covers previous fields */
 109         rte_compiler_barrier();
 110         p = (uintptr_t)&mb_def.rearm_data;
 111         rxq->mbuf_initializer = *(uint64_t *)p;
 112
 113         return 0;
 114 }
 115
 116 /* Stub for linkage when arch specific implementation is not available */
 117 uint16_t __attribute__((weak))
 118 virtio_recv_pkts_vec(void *rx_queue __rte_unused,
 119                      struct rte_mbuf **rx_pkts __rte_unused,
 120                      uint16_t nb_pkts __rte_unused)
 121 {
 122         rte_panic("Wrong weak function linked by linker\n");
 123         return 0;
 124 }